A typical flush toilet installation includes a flush tank with an outlet passage communicating with the bowl of the toilet, a valve seat defined within the flush tank and controlling the entry to the outlet passage, and a flapper valve for seating coaction with the valve seat to control the discharge of water from the flush tank to the bowl through the outlet passage.
Many types of flapper valves have been used over the years to control the outlet passage of the toilet and many mounting constructions have been provided to accommodate the movement of the flapper valve between its opened and closed positions. For example, in installations including a separate overflow tube with integral ears or trunions, the flapper valve is pivotally mounted on the ears or trunions on the overflow tube; in installations including a separate overflow tube which does not have integral ears or trunnions, various clamp and wire arrangements are provided to mount the valve on the overflow pipe; and in installations having an overflow passage built into the tank and therefore not having a separate overflow tube, the valve is mounted on a separate anchoring post upstanding from the bottom wall of the flush tank. A different flapper valve construction is therefore required for each mounting arrangement so that, in order to be in a position to replace all of the common flapper valve constructions, a manufacturer must build three or more different types of flapper valves and a supplier must stock an inventory of three or more types of flapper valves. Whereas various attempts have been made in the past to provide flapper valves that are able to accommodate two or more of the common flapper valve mounting arrangements, these multi-purpose valves have had only modest commercial success since they have either been unduly complicated and expensive in construction and/or have failed to function effectively in one or more of the plurality of mounting applications for which they are intended.